Rice stands for Race inspired cosmetic enhancements. These would be spoilers big enough to knock over a stop light that have no aerodynamic benefits, cheap hubcaps made to replicate rims such as volks, Drop center BBS ect. 24 inch chrome rims on cars like a Civic or camry, Ugly or stupid looking vinyls, ugly non functional body kits or wide bodys, neon lights, speakers that fill the whole trunk.
an example of non rice would be a clean Honda Civic 18 inch volk rims a few stickers here and there lowered an inch or two and most of the money put into the engine.
Civic Owner: ok Pay up you lost
Sentra Owner: How the hell did you beat me i don't get it YO
Civic Owner: Maybe you shouldn't spent $900 dollars on that spoiler of you'res
Sentra Owner: But it makes it faster YO
Civic Owner: Not with the small power you have it's just RICE